Exercise bicycle



FIG. 1 is a side elevational view of an exercise bicycle showing my new design, the side opposite being a mirror image;

FIG. 2 is a right end elevational view thereof;

FIG. 3 is a left end elevational view thereof;

FIG. 4 is a top plan view thereof; and,

FIG. 5 is a bottom plan view thereof. 

The ornamental design for an exercise bicycle, as shown and described. 